At present, the global epidemic situation of infectious diseases is becoming more and more serious and complex, which brings difficulties and challenges to the prevention and control of infectious diseases and poses a serious threat to public health and safety. The premise and basis of the prevention and control of infectious diseases is to carry out scientific risk assessment. Firstly, the common risk assessment methods were introduced, and the limitations of these one-time static assessment methods were analysed. Then the dynamic risk assessment methods for the transmission of infectious diseases were introduced, and expressing the transmission of infectious diseases as scenarios was proposed. Scenarios were deduced to predict the future development trends of infectious diseases. It is of great positive significance to evaluate the risks of infectious diseases according to different development trends, and realize the transition from traditional “prediction-response” to “scenario-response” for improving the emergency management capability of the transmission of infectious diseases.

External disturbance is an important cause of underground pressure pipeline damage, which leads to accidents, and it is crucial to study the risk of damage caused by external disturbance and come up with proper prevention and control measures. We reviewed literature on risk identification of underground pressure pipelines damage due to external disturbance was conducted, and a list of risk factors was formed. Based on the list of risk factors, fault tree analysis was carried out on underground pressure pipelines damage caused by external disturbances, and risk prevention and control measures were proposed through the calculation of minimum cut sets, minimum path sets, and structural importance, in hopes of providing reference for the normal operation of underground pressure pipelines.

In order to study the evacuation process of crowd in evacuation space containing four exits (two exits on one side), a simulation environment was built by using multi-agent simulation platform NetLogo, and the evacuation simulation model was constructed. The influence of exit location, exit width and evacuee number on the evacuation efficiency was studied, the results show that: with the exit moving to the middle, the evacuation time first decreases and then increases, and the decreasing rate of evacuation time decreases gradually and the increasing rate increases gradually; when the evacuee number is small, the evacuation time decreases with the increase of exit width, until the evacuation time remains unchanged when the exit width is large enough. However, when the evacuee number is large, the evacuation time in different positions decreases with the increase of exit width, and the overall decrease rate decreases; with the exit moving to the middle, the increasing rate of evacuation time with the increase of evacuee number at different exit widths decreases at first and then increases. The research results can provide some reference value for the evacuation exit design of building and emergency command of crowd evacuation.